More men with than men without childhood sexual abuse (CSA) histories report sexual behavior that has high risk for HIV transmission. Since 1-in-6 to 1-in-14 men report histories of childhood sexual abuse (CSA), the population of men with CSA histories is a numerous and suitable one for research that seeks to understand evolving sexual risk behavior patterns that have HIV infection risk. Such an effort is critical at a time when the pattern of long-term declines in gonorrhea and syphilis rates have reversed due to rate increases in men. Our specific interests in the current study of male sexual risk behavior patterns emanate from preliminary findings of the principal investigator. This work has indicated that co-morbid posttraumatic stress disorder (PTSD) and depression acts as both a mediator and a moderator of the association between CSA and sexual risk behavior. The subgroup with CSA/PTSD/depression had the highest lifetime sexual partners (mean, 54.3). To understand these findings better, we have evolved for use in men a model originally developed to describe the mediating pathway from CSA to adult risk in women. We propose further study of this newly identified role of co-morbid PTSD/depression on men's HIV-related sexual risk behavior by adjusting more fully for potentially confounding/effect-modifying variables and by doing so in analyses of lifetime and current sexual behavior assessments. We also will test the model we have evolved to explain the mediating/moderating pathway between CSA and lifetime sexual risk behavior in men by employing structural equation modeling (SEM) to assess relationships between CSA and resilience, psychopathology, sexual maladjustment, sexual networks, and sexual activity that have HIV infection risk. We propose a cross-sectional, random-digit-dial (HDD) survey of 1,200 men from high AIDS incidence areas of Philadelphia County; 300 of these will be oversampled heterosexually- and homosexually-identifying men who have sex with men (MSM) recruited for exploratory analyses of whether the noted SEM is applicable to MSM as well as to men who only have (had) sex with women. Study results will inform construction and allow testing of a developing, integrative model for men that identifies factors that mediate and moderate linkages between CSA and HIV-related sexual risk. From this model, multidimensional HIV risk reduction interventions can be built.